Re: [PATCH v7 2/2] diff-files: integrate with sparse index

> Only the latter represents incorrect behavior. If we're aren't expanding the
> index for a case that was causing index expansion before *and* the
> user-facing behavior is as-expected, that's the best-case scenario for a
> sparse index integration!
>
> Taking a step back, it's important to remember that the overarching goal of
> the project is not just to switch 'command_requires_full_index' to '0'
> everywhere, but to find all of the places where Git is working with the
> index and make sure that work can be done on a sparse directory.
>
> In most cases, it's possible to adapt an index-related operation to work
> with sparse directories (albeit with varying levels of complexity). The use
> of 'ensure_full_index()' is reserved for cases where it is _impossible_ to
> make Git perform a given action on a sparse directory - expanding the index
> completely eliminates the performance gains had by using a sparse index, so
> it should be avoided at all costs.
>
> I hope that helps!